Conventionally, as a covering processing tool for covering a cable connection portion that connects cables to each other, a covering processing tool provided with a tubular and hollow diameter expansion holding member that can be disassembled and an elastic tubular member made from an elastic material such as rubber held in a state of diameter expansion on an outer peripheral side of the diameter expansion holding member is known (for example, see Patent Literature 1). With this covering processing tool, the connection portion is covered by the elastic tubular member contracted by disassembling the diameter expansion holding member. Moreover, covering is further performed by the elastic tubular member contracted by setting the diameter expansion holding member on both end portions of the covering portion and disassembling the diameter expansion holding member.